Keeping your hot tub water clean comes down to three habits: test at least twice a week, shock once a week, and change the water every 3 to 4 months. Maintain pH between 7.2 and 7.8 and free chlorine between 1 and 3 ppm. With the Gecko App Test Strip Scanner, the weekly test takes 30 seconds. With Gecko waterlab, pH, ORP, and temperature are monitored continuously.
KEY DATA: In a hot tub at 100 to 104 degrees Fahrenheit, bacteria can develop to harmful levels within 2 to 4 hours when sanitizer drops to zero. Regular monitoring is not optional. It is the primary protection against waterborne illness.
The 3-Habit System for Clean Hot Tub Water
Habit 1: Test at Least Twice a Week
Pick two fixed days, for example Monday and Thursday. On each day, test your water with a test strip. You are checking four things:
pH: should be between 7.2 and 7.8
Free chlorine or bromine: should be between 1 and 3 ppm
Total alkalinity: should be between 80 and 120 ppm
Calcium hardness: should be between 150 and 300 ppm
If everything is in range, you are done. If something is off, add the appropriate product and retest the next day.
With the Gecko App: The Strip Scanner reads all parameters from a photo in 20 seconds and tells you exactly what to add based on your chemicals. No color charts, no math.
Habit 2: Shock Once a Week
Shocking means adding an oxidizing product to destroy organic contaminants that regular sanitizer cannot fully eliminate: body oils, sweat, cosmetics, and sunscreen. Do this after your last session of the week so the water has time to clear overnight. Think of it as a weekly reset for your water.
Habit 3: Change the Water Every 3 to 4 Months
Over time, dissolved solids accumulate in the water and it becomes harder to balance. When that happens, drain the spa completely, clean the shell, and refill with fresh water. A full water change for a 300 to 400 gallon hot tub takes roughly 30 to 45 minutes. It is the single most impactful maintenance task you can do.
One Extra Thing: Rinse Your Filters
Every two weeks, remove your filters and rinse them with a garden hose. Dirty filters cannot clean the water, no matter how good your chemistry is. Replace filters completely every 12 to 18 months.
Want the Water to Watch Itself?
The three habits above cover everything you need. But if you want to go further, Gecko waterlab removes daily monitoring from your plate entirely.
Gecko waterlab is a continuous water monitoring system installed discreetly under your spa. A single probe measures pH, ORP, and temperature around the clock and sends automatic alerts to the Gecko App the moment something drifts. No strip, no guessing.
Once a month, the app prompts you to submit a quick water report for the parameters a sensor cannot measure: total alkalinity, calcium hardness, and cyanuric acid. That is the only recurring action waterlab asks of you.
KEY DATA: Gecko waterlab requires the in.touch 3+ controller. It is not compatible with the in.touch 3 standard or in.touch 2.
Frequently Asked Questions
Q: How do you keep hot tub water clean?
A: Test at least 2 to 3 times per week, shock weekly, rinse filters every two weeks, and change water every 3 to 4 months. Maintain pH between 7.2 and 7.8, and free chlorine between 1 and 3 ppm.
Q: What pH should hot tub water be?
A: Between 7.2 and 7.8. Below 7.2 irritates skin and corrodes equipment. Above 7.8, sanitizer loses effectiveness.
Q: What is the easiest way to test hot tub water?
A: The Gecko App Premium Test Strip Scanner: dip a test strip, take a photo, and the app tells you exactly what to add. No interpretation needed.
Q: What is Gecko waterlab?
A: A continuous monitoring system installed under the spa. A probe measures pH, ORP, and temperature 24 hours a day and sends automatic alerts when something drifts. Requires in.touch 3+.